Hugh Schofield

Shrouded in an official darkness rendered all the more impenetrable by random leaks, rumours, and - one often suspects - downright fabrications, the Diana enquiry rumbles methodically towards its conclusion later this spring.

Never accused of undue haste, the French justice system is moving with a thoroughness that an inquest of this importance no doubt deserves, but with a stealth that leaves a starved international press gasping for new stories.

The result has been open season for Diana gossip-mongers. The last weeks have seen reports on:

The Australian video shock
An Australian couple were reported to have footage of the scene of the crash moments after it happened. Police were said to be "desperate" to get their hands on the tape - it turned out to be completely irrelevant.

The discovery of the second car shock
Police were put on the trail of a white Fiat Uno, similar to the one they are still hunting.

It was reported to have had its front wing repaired, and then been sold in November - by a well-known paparazzo. The implication was that a photographer had been in the mysterious second car that may have caused the accident.

But it turned out that the lead had been discovered by investigators acting for the al-Fayed family. Once again police dismissed it as irrelevant.

The Henri Paul millions shock
Sources "close to the investigation" revealed that the dead driver of the crashed limousine had had large amounts of money mysteriously lodged in his bank account shortly before the accident.

The rumour-mill suggested there was a drugs connection. Police dismissed it as irrelevant.

The serialised Princess

Short of hard facts, the popular press fixes on the wildest of unverifiable trivia to drive the Diana story forward.

Meanwhile at the other end of the market, the first books are appearing alleging to tell the full story about the Princess's death.

The most publicised of these, by two Time magazine correspondents, has been serialised in various papers. Its chief claim to fame is the interview it contains with Mohammed Al Fayed, father of Dodi.

In it he says he is 99 per cent certain the crash was caused deliberately by unknown persons acting to prevent his son's and Diana's impending marriage.

As no proof of this was vouchsafed, the police once again dismissed it as irrelevant. In fact, the police now say they are increasingly irritated by the succession of ludicrous fantasies masquerading as plausible theories about how and why the Princess died.

Hiding behind their own official secrecy, the investigators maybe have only themselves to blame for the speculation. A more open policy might put paid to the rumour-mongers.

But at heart the police have a point. From the start nothing has emerged to shake the basic facts in the case: a drunk chauffeur driving at 90 mph through a busy city centre lost control, having possibly - or possibly not - glanced another vehicle.

There is nothing out of the ordinary in that.

Just a dead princess.

• The grief of millions
• On the Net: Truly the People's Princess
• Deaths a fertile ground for conspiracy theories
• The battle for Diana's lucrative legacy
• the changing face of the monarchy